[PATCH v8 02/11] migration: Make save_snapshot() return bool, not 0/-1

From: "Daniel P. Berrangé" <berrange@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Kevin Wolf" <kwolf@redhat.com>,
	"Peter Krempa" <pkrempa@redhat.com>,
	"Pavel Dovgalyuk" <pavel.dovgalyuk@ispras.ru>,
	"Denis V. Lunev" <den@virtuozzo.com>,
	qemu-block@nongnu.org, "Juan Quintela" <quintela@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	"Max Reitz" <mreitz@redhat.com>,
	"Pavel Dovgalyuk" <pavel.dovgaluk@ispras.ru>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"John Snow" <jsnow@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>
Subject: [PATCH v8 02/11] migration: Make save_snapshot() return bool, not 0/-1
Date: Thu, 26 Nov 2020 17:35:12 +0000	[thread overview]
Message-ID: <20201126173521.137580-3-berrange@redhat.com> (raw)
In-Reply-To: <20201126173521.137580-1-berrange@redhat.com>

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Just for consistency, following the example documented since
commit e3fe3988d7 ("error: Document Error API usage rules"),
return a boolean value indicating an error is set or not.

Acked-by: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/migration/snapshot.h |  9 ++++++++-
 migration/savevm.c           | 16 ++++++++--------
 replay/replay-debugging.c    |  2 +-
 replay/replay-snapshot.c     |  2 +-
 4 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/include/migration/snapshot.h b/include/migration/snapshot.h
index c85b6ec75b..0eaf1ba0b1 100644
--- a/include/migration/snapshot.h
+++ b/include/migration/snapshot.h
@@ -15,7 +15,14 @@
 #ifndef QEMU_MIGRATION_SNAPSHOT_H
 #define QEMU_MIGRATION_SNAPSHOT_H
 
-int save_snapshot(const char *name, Error **errp);
+/**
+ * save_snapshot: Save an internal snapshot.
+ * @name: name of internal snapshot
+ * @errp: pointer to error object
+ * On success, return %true.
+ * On failure, store an error through @errp and return %false.
+ */
+bool save_snapshot(const char *name, Error **errp);
 int load_snapshot(const char *name, Error **errp);
 
 #endif
diff --git a/migration/savevm.c b/migration/savevm.c
index 221b85e07c..8304b5cd0a 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2725,7 +2725,7 @@ int qemu_load_device_state(QEMUFile *f)
     return 0;
 }
 
-int save_snapshot(const char *name, Error **errp)
+bool save_snapshot(const char *name, Error **errp)
 {
     BlockDriverState *bs;
     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
@@ -2738,29 +2738,29 @@ int save_snapshot(const char *name, Error **errp)
     AioContext *aio_context;
 
     if (migration_is_blocked(errp)) {
-        return ret;
+        return false;
     }
 
     if (!replay_can_snapshot()) {
         error_setg(errp, "Record/replay does not allow making snapshot "
                    "right now. Try once more later.");
-        return ret;
+        return false;
     }
 
     if (!bdrv_all_can_snapshot(errp)) {
-        return ret;
+        return false;
     }
 
     /* Delete old snapshots of the same name */
     if (name) {
         if (bdrv_all_delete_snapshot(name, errp) < 0) {
-            return ret;
+            return false;
         }
     }
 
     bs = bdrv_all_find_vmstate_bs(errp);
     if (bs == NULL) {
-        return ret;
+        return false;
     }
     aio_context = bdrv_get_aio_context(bs);
 
@@ -2769,7 +2769,7 @@ int save_snapshot(const char *name, Error **errp)
     ret = global_state_store();
     if (ret) {
         error_setg(errp, "Error saving global state");
-        return ret;
+        return false;
     }
     vm_stop(RUN_STATE_SAVE_VM);
 
@@ -2846,7 +2846,7 @@ int save_snapshot(const char *name, Error **errp)
     if (saved_vm_running) {
         vm_start();
     }
-    return ret;
+    return ret == 0;
 }
 
 void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live,
diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c
index 7ad0a37179..c5d3da1e80 100644
--- a/replay/replay-debugging.c
+++ b/replay/replay-debugging.c
@@ -324,7 +324,7 @@ void replay_gdb_attached(void)
      */
     if (replay_mode == REPLAY_MODE_PLAY
         && !replay_snapshot) {
-        if (save_snapshot("start_debugging", NULL) != 0) {
+        if (!save_snapshot("start_debugging", NULL)) {
             /* Can't create the snapshot. Continue conventional debugging. */
         }
     }
diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c
index e26fa4c892..4f2560d156 100644
--- a/replay/replay-snapshot.c
+++ b/replay/replay-snapshot.c
@@ -77,7 +77,7 @@ void replay_vmstate_init(void)
 
     if (replay_snapshot) {
         if (replay_mode == REPLAY_MODE_RECORD) {
-            if (save_snapshot(replay_snapshot, &err) != 0) {
+            if (!save_snapshot(replay_snapshot, &err)) {
                 error_report_err(err);
                 error_report("Could not create snapshot for icount record");
                 exit(1);
-- 
2.28.0


